attachments: Query and Download Feature Service Attachments

In arcgislayers: Harness ArcGIS Data Services

Query and Download Feature Service Attachments

Description

Query attachment information using query_layer_attachments() and download attachments using download_attachments().

Feature Services can contain attachments that are associated with a single feature ID.

• Use add_features() to add attachments to a feature service

• Use update_features() to update the attachments of a feature service

• Use query_layer_attachments() to list attachments of a feature service

• Use download_attachments() with the results of query_layer_attachments() to download the attachments from a feature service locally

Usage

add_attachments(
  x,
  feature_id,
  path,
  file_name = basename(path),
  .progress = TRUE,
  token = arc_token()
)

query_layer_attachments(
  x,
  definition_expression = "1=1",
  attachments_definition_expression = NULL,
  object_ids = NULL,
  global_ids = NULL,
  attachment_types = NULL,
  keywords = NULL,
  return_metadata = TRUE,
  ...,
  token = arc_token()
)

download_attachments(
  attachments,
  out_dir,
  ...,
  overwrite = FALSE,
  .progress = TRUE,
  token = arc_token()
)

update_attachments(
  x,
  feature_id,
  attachment_id,
  path,
  .progress = TRUE,
  token = arc_token()
)

Arguments

x	an object of class FeatureLayer, Table, or ImageServer.
feature_id	a vector of object IDs that corresponds to the feature of the corresponding attachment_id.
path	a vecetor of the same length as feature_id indicating where the attachment exists.
file_name	the name of the file. Defaults to the basename(path). Must be the same length as feature_id.
.progress	default TRUE. Whether a progress bar should be provided.
token	an httr2_token as created by auth_code() or similar
definition_expression	default 1 = 1. A SQL where clause that is applied to the layer. Only those records that conform to this expression will be returned. This parameter is required if neither object_ids or global_ids have been defined.
attachments_definition_expression	default NULL. A SQL where calsue that is applied to the attachment metadata. only attachments that conform to this expression will be returned.
object_ids	mutually exclusive with definition_expression and global_ids. The object IDs of the features to query attachments of.
global_ids	mutally exclusive with definition_expression and object_ids. The global IDs of the features to query attachments of.
attachment_types	default NULL. A character vector of attachment types to filter on.
keywords	default NULL. A character vector of the keywords to filter on.
return_metadata	default TRUE. Returns metadata stored in the exifInfo field.
...	unused
attachments	a data.frame created by query_layer_attachments(). Must contain the columns name, url, and contentType.
out_dir	the path to the folder to download the file
overwrite	default FALSE. A
attachment_id	the ID of the attachment—this corresponds to the id column returned from query_layer_attachments()

Details

To rename or otherwise modify an attachment in a Feature Service, you must first download that attachment, modify the file on disk, and then upload it again. This is a limitation of ArcGIS Online and Enterprise. If you'd like to see this changed, please submit a community idea at community.esri.com.

If any requests fail, the requests are added as as the errors attribute to the resultant data.frame.

Value

query_layer_attachments() returns a data.frame.

download_attachments() returns a list. If an error occurs, the condition is captured and returned in the list. Otherwise the path to the file that was downloaded is returned.

a data.frame with 2 columns returning the status of the update.

References

See API documentation for more.

ArcGIS REST API Documentation

See API documentation for more.

Examples

## Not run: 
if (interactive()) {
library(arcgisutils)

# authenticate
set_arc_token(auth_user())

# open a feature service
feature_layer <- arc_open("your-item-id") |>
  # layer ID of the feature service
  get_layer(0)

# create a list of features to update
features <- c(1,2,3)

# create a list of files to upload as attachments
attachment_files <- c("path/to/file1.png", "path/to/file2.png", "path/to/file3.png")

# add the attachment files to the features in the feature layer
add_response <- add_attachments(feature_layer, features, attachment_files, use_basename=TRUE)
}

## End(Not run)
## Not run: 
# create a url path that isn't too wide for CRAN
furl <- paste(
  c(
    "https://services1.arcgis.com/hLJbHVT9ZrDIzK0I",
    "arcgis/rest/services/v8_Wide_Area_Search_Form_Feature_Layer___a2fe9c",
    "FeatureServer/0"
  ),
  collapse = "/"
)
# connect to the layer
layer <- arc_open(furl)

# get the attachment info
att <- query_layer_attachments(layer)

# download them to a path
download_attachments(att, "layer_attachments")

## End(Not run)
## Not run: 
if (interactive()) {
library(arcgisutils)

# authenticate
set_arc_token(auth_user())

# open a feature service
feature_layer <- arc_open("your-item-id") |>
  # layer ID of the feature service
  get_layer(0)

# query attachment layer information
attachments <- query_layer_attachments(feature_layer)

# create a temporary directory
tmp <- tempdir()

# download attachments to the temporary directory
download_attachments(attachments, tmp)

# get original paths
fps <- file.path(tmp, attachments$name)

# prepend attachments with the date
new_filenames <- paste0(Sys.Date(), "-", basename(attachments$name))

# create new file paths
new_fps <- file.path(dirname(fps), new_filenames)

# rename the files
file.rename(fps, new_fps)

# update the attachments
update_res <- update_attachments(
  feature_layer,
  # OID of the feature <> attachment relationship
  attachments$parentObjectId,
  # the attachment ID
  attachments$id,
  # the path to the attachment on disk
  new_fps
)
}

## End(Not run)

arcgislayers documentation built on March 4, 2026, 9:06 a.m.